In the tech world, everything is always “go, go, go!” There’s never any slowing down when it comes to the evolution of tech; it’s always on to the next, big thing. So it should hardly come as a surprise that before wearables have really caught on and permeated the mainstream market, that technology is already starting to evolve to an extremely invasive version: implantables.

Profusa, a South San Francisco-based tech company is already so over the wearable craze. They’re working on body sensing technology that will be injected directly into a person that would perform all the features of your standard wearable fitness tracker, and more. Taking to the CES showroom, Profusa demonstrated the Lumee Oxygen Sensing System, a tiny, grain-of-rice sized biocompatible sensor about as thick as a couple human hairs. The device is made to be injected into one’s skin to monitor oxygen levels in their surrounding tissue. Constructed using hydrogel, the sensor resembles the flexibility and feel of a contact lens.

If injecting yourself with technology is a little too extreme for you, Profusa’s aim for the sensor will be narrowly focused, at least initially. The company plans to target their implantable to medical facilities as a way of monitoring peripheral artery disease and wound healing. If all is successful, the applications of the device may spread outward, specifically to athletes in order to track muscle performance.

In order to construct a device that could be injected into one’s body and would be able to thrive there essentially forever, without creating scar tissue or having your body’s natural system reject the foreign object, Profusa spent a lot of time researching and designing this little guy. They came to the conclusion that a design resembling a sponge made the most sense – the sensor has microscopic holes that allow and will facilitate the growth of cell tissue while its rounded edges blend seamlessly inside one’s skin. Coated with a fluorescent dye that reacts to oxygen, the sensor will glow when hit by certain wavelengths of light. The sensor can be read by shining light on the skin where the sensor was injected and using an optical reader to detect these emissions. Currently, this sort of device is handheld and can transmit the data into a smartphone.

Profusa hopes the Lumee Oxygen Sensing System will be given the go-ahead in Europe to monitor peripheral artery disease in the coming months, with FDA approval to follow. If all goes well with their oxygen monitoring implantable, Profusa already has its sights set on developing similar injectable sensors to monitor urea, lactation, glucose and creatinine levels. A device implanted in your body that monitors aspects of your health and goes wherever you go by default could be revolutionary when it comes to human health and fitness.